Typewriting machine



ug- 18, 9 F. WALSLEBEN 31 3 TYPEWRITING" MACHINE eats-Sheet 1 Aug. 18, 1931.

F. WA'LSLEBEN 1,819,215

TYPEWRITING MACHINE Filed July 5 192 s 5 Sheets-Sheet 2 Aug. 18, 1931. F. WALSLEBEN TYPEWRITING MACHINE Filed Julyfi, 1928 5 Sheets-Sheet 3 FIG 7 45 0 I62? 52 I55 4% 110 I07 I04 Z3 awe/Wm:

.Aug. 18,1931, I F/WALSLEBEN 1,8

,TYEEIWRITING MACHINE Filed July 6, 1928 .5 Sifeets-Siieet 4 FIG.9.

g- 1931. F. WALSLEBEN I TXPEWRITING MACHINE Filed July 6, 1928 5 Sheets-Sheet 5 Patented Aug. 18, 1931 NET!" S'ETA'FE FRED WALSLEBEN, OF ROCKVILLE CENTER, NEW YORK, ASSIGNOR T6 UNDERWOOD ELLIOTT FISHER GQMPANY, 0E5 NEVI YGRK, N. Y., A. CGRE ORATION OF DELAWARE TYPEWRITING MACHINE Application. filed July 6,

This invention relates to a universal variable line-spacing mechanism for a type writer-platen in which the unit of line-space distance may be micrometrically varied and in which different settings may be made for spacing predetermined multiples of said unit.

An object of the invention is to provide an efficient and compact mechanism for the type of machine in which the platen is mounted in a case-shifting frame or equivalent device, and which frame or device is carried by the usual letter-feeding carriage and is shiftable relatively to said carriage. A manually-operable reciprocatory linespace operator, preferably a lever mounted upon the letter-feeding carriage, is employed and the mechanism connecting said reciprocatory lever to the platen is organized so that the possibility of lost motion and binding of the line-spacing mechanism between the lever and platen, largely due to the non rigid manner in which the case-shifting frame may be supported, is substantially minimized. The mechanism is further organized so that the force of its reaction upon the platen-frame is negligible and hence does not tend to twist said platen-frame or dislodge it from its bearings.

To these and other ends, the mechanism is organized so that all of its controlling parts are carried by, and are solidly supported by the letter-feeding carriage as distinguished from the heretofore-observed practice of mountin some, if not all, of such controlling parts upon the weakly supported platenframe. A clutch and controlling device therefor, whereby only the advance movement of the reciprocatory line-space lever is effective to rotate the platen, are employed and constitute controlling parts of the mechanism. In the novel organization it is contrived to solidly support said clutch and its controlling device upon the letter-feeding carriage.

A form of clutch in which teeth interlock when said clutch is engaged, is preferably employed and on account of the aliquant relation between the clutch-tooth spacing and the variable line spacing to be effected, a line 1928. Serial No. 290,775.

junction with the fine clutch-tooth pitch,

renders the aforesaid aliquant relation of the clutch-tooth pitch to the line spacing negligible and thus the uniformity of said line spacing is practically unimpaired. The driven side of the clutch may be connected to a rotary p'laten-driver preferably in the form of a gear whose axis extends substantially parallel to the direction in which the platen-frame is moved for case shifting. As will be shown, said platen driver or gear may, in the simplest disposal thereof, be directly connected to the driven member of the clutch and thus form part of said driven member. Means whereby the clutch is speeded up may also be solidly supported on the carriage-frame.

For compactness, of the mechanism, the

clutch and the platen driver or gear may be mounted coaxially with the line-space lever preferably upon an extension of the fulcrum of said lever. For speeding up the clutch and platen-driver, a pinion connected to the drivingside of the clutch may mesh with a reciprocatory sector which may be operatively connected to the line-space lever by a link having one end pivotally connected to anarm of the sector, theother end of the link being connected to an arm of the line space lever. The relative proportions of the sector and pinion meshing therewith may be such as to'secure the desired large angular displacement of the clutch as compared to the usually limited angular displacement of the line-space lever.

Means may be provided for micrometrically varying either the length of the link-arm of the line-space lever or the length of the link-arm of the aforesaid sector. In the illus trated and preferred form of the invention it is the length of theline-space lever-arm that is thus varied, and by so varying said length,

ion

the extent of line spacing resulting from a given movement of the line-space lever is correspondingly varied.

The rotary platen driver or gear has the same large rotary displacementas the clutch, and may be connected to the platen by a train of reducing gearing which may be retained in a mounting or fixture which may bear upon, or be otherwise centered by, said platenaxle to which one end of said train is keyed. In its simplest form saic train, which serves to translate the large rotation of the platendriver into platen rotation of line-space ex tent, may consist of a bevel gear keyed to the platen-axle and meshing with a substantially smaller bevel pinion, said latter pinion being compounded with a substantially larger gear that may mesh with the platen driver or gear on the letter-feeding carriage.

he mechanism may be organized so that the direction of the reaction of the platendriving gear, supported by the letter-feeding carriage upon the meshing gear of the reducing train carried by the platen-frame, is in av direction substantially longitudinal of the carriage and platen-frame. It will be understood, inasmuch as the displacement, at the point where the platen-driving gear on the letter-feeding carriage meshes with the large gear of the reducing train, is large as compared with the required extent of platen-rotation, that the force of reaction upon the platen-franie is correspondingly small; that is to say, the force of said reaction being inversely proportional to the displacement of the driving teeth of the platen-driver, it follows that the greater the displacement of said platendriving gear-teeth the less will be the reaction upon the platen-frame. Consequently the angular displacement and the diameter of the platen-driving gear on the letter-feeding carriage are made aslarge as is compatible with the general design of the mechanism. This large angular displacement of the platendriving gear is conveniently afforded by reason of direct connection of said latter gear to the aforesaid clutch which, as stated, also has a large angular displacement.

By suitable elongation of teeth, the platendriving gear on the. letter-feeding carriage may always engage the gear on the platenframe meshing therewith, irrespective of the case-shift position of said platen-frame, it being understood that the teeth of said latter gear may be parallel to the teeth of the platendriving gear which extend parallel to the direction in which the platen-frame is shifted.

A multiple space stop is provided to secure different multiples of the micrometrically variable line-space unit. Said stop may be in the form of an arm fulcrumed on the linespacelever fulcrum. A segment having slots, notches or other suitable formations, located to establish the different stations, may be provided to hold the multiple space stop-arm,

which accordingly may have a portion which may be set into said slots, notches or formations.

The line-space multiple desired is determined preferably by controlling the extent of movement of the line-space lever, and accordingly the stop-arm may have a stop abutment for said line-space lever. The stop-arm, as will be shown, has provision which is novel inits simplicity and effectiveness for retaining it at its different stations, said provision also permitting ready release of the stop-arm preparatory to shifting it to a new position.

An important feature of the invention is that aside from the train of reducing gearing carried by the platen frame, all the other parts, including the controlling parts, of the mechanism, may be assembled in a compact and complete suit which may be readily attached to, or removed from, the letter-feeding carriage. By organizing the mechanism into such complete unit, proper adjustment of the mechanism is easily maintained and may be made as part of a factory organized process, so that all that is necessary in case the mechanism has to be supplied to a machine already in service, is to attach the unit by screws to the fran'ie of the letter-feeding carriage. Similarly, the train of reducing gearing and the mounting or fixture therefor, may b:- assembled as a unit which may be readily slipped onto the platen-axle and mav be provided with a portion which may serve to anchor said fixture or mountin to a suitable part of the platen-frame.

Where the novel organization is incorporated in two such separate and complete units, the only adjustment to be made in attaching said units to a typewriter is to secure proper meshing of the platen-driving gear of the one unit attached to the letter-feeding carriage with the mating gear of the reducing-train unit attached to the platen-frame or axle, and such adjustment for proper meshing is easily made, as will be seen later.

Each unit may be covered by a casing that serves as a protective covering and conduces to neat appearance. The casing of the main unit on the letter-feeding carriage may be formed to expose the handle of the line-space lever and other parts which are to be manipulated for adjusting the line-space distance. Said latter casing may also be formed to expose the portion of the platen-driving gear which engages the mating gear of the reducing train.

The platen-frame unit, including the train of reducing gearing, may be provided with a rotatable finger-knob disposed for easy access thereto and connected to the reducing train in such manner that it has a large angular displacement as compared with platenrotation effected by manipulating said finger-knob. Thus said finger-knob may serve for fine adjustment of a work-sheet on the platen to the prlntlng line.

This invention is in the nature of an 1111,-

prove-1nent upon the invention disclosed in the application of B. C. Stickney, Serial No.

v maximum spacing.

Figure 2 is a side elevation of the mechanism, some of the parts being shown broken away and in section.

Figure 3 is a top plan view of the mechanism, showing the reciprocatory line-space operator or lever at the end of its line-spacing stroke, and also showing details not shown in the top plan view of Figure 1.

Figure 4: is a side elevation of the mecha- 'nism similar to Figure 2, and showing details not brought out in Figure 2.

Figure 5 is a top plan view of the mechanism similar to Figures 1 and 3, showing do tails not brought out in said latter figures. Figure 5 also indicates the mechanism as set for double spacing: of a line-space unit of minimum extent.

Figure 6 is a side elevation of the mechanism, showing details of the casings enclosing the mechanism.

Figure 7 is a front elevation of the unit attached to the lettenfeeding carriage, and illustrates further details of the casing enclosing said unit.

Figure 8 is a side elevation, showing the multiple line-space-lever stop withdrawn from a holding notch preparatory to shifting itto another position.

Figure 9 includes several views of details l of means for controlling engagement and disengagement of the clutch.

Figure 10 is a top plan view of a mounting for the unit that is attached to the letterfeeding carriage.

Figure 11, is a rear elevation, showing details of the reducing gear train and its mounting, and the relation thereof in respect to the platen-frame and platen-axle; the view in this figure extending longitudinally of the platen-axle.

. Figure 12 is a side elevation of the mounting shown in Figure 10.

Figure 13 shows, in perspective, the mounting for the aforesaid reducing gear train carried by the platen-frame.

Figure 14 is a perspective diagram of the mechanism as seen from the front of the letter-feeding carriage.

The novel line-spacing organization is herein illustrated as adapted for the well kn own Underwooditypewriter, in which a revoluble platen is secureditoa. platen-axle 21 journaled in. end members of the usual.- platen-frame. Said platen-frame is herein. represented by the left-end frame-member22' thereof and moves up and down. relatively to a letter-feeding carriage-frame 23bymeansof the usual case-shiftingdevices, not shown. Of said carriage-frame there is shown only: the forward. and; left end portion which sup-- ports the mechanism of the invention.

A reciprocatory line-spacelever, generally designated by the number. 25, isbest made in. two parts, one part of a metal stamping 26, in which are embodied thefulcrum endand variable arm of the lever, and the other'pa-rt a moldedhandle 27 which may be securedto said stamping by rivets 28. (Figure 3). The stamping 26 has formed therein. a slot 29in which a slide 30, having retaining grooves closely fitting the sides of-saidslot,.m-ayserve. to shift a pin 31 nearer to or furthen away from the fulcrum. of the lever. Thus, for: varying the line-space distance said lever is provided with an arm of variable length determined by the position, of the pin 81,. and for a given movement of the line-space lever the displacement of the pin 31, and consequently the line-space distance, depends on: the distance of said pin 31 from the fulcrum of the lever. Means for microme'trically varying said. distance will be described'laten;

A clutch, which will be described, is em ployed in order that only the advance stroke of the line-space lever is effective to rotate the platen, said clutch serving to complete operative connection between said; line-space: lever and the platen by and during the advance stroke of the lever,.and' conversely serving topermitthe reverse stroke of; said lever to take place without reversingthe platen; The clutch also serves to keep the connection between the line-space lever and the platen normally open in orderthat the platen may:

as usual be independently-rotated. The driv ing side of the clutch is keyed to the line-space lever and the driven side of the clutch. is,

' the driven side of the clutch is keyed to the platen will be explained further on. For line-space uniformity, governed by reasons which will become apparent, the clutch operates through a substantially larger degree. of rotation than the requiredline-space rotation of the platen. Means whereby the driving side of the clutch is keyed to the line-space lever and whereby the clutch is speeded up will now be described. The variable arm of the line-space lever, which may be regarded as terminating in the pin 31, is connected by means of a link 32 to an arm 34: of a reciproca-z tory gear-sector 35, one end. of: saidli-nk-fibting'over the pin 31, the other end:of1 the link being pivotally connected at 33 to-= said arm. 34:. The gear-sector 35imeshes-wi-t h pinion:

36 to which may be secured an arm 37, on the outer end of which there may be pivotall mounted a pawl 38 to form the driving side of the clutch. The driven side of the clutch is embodied in a ratchet-wheel 39 which said pawl may engage. The teeth of the pawl and ratchet-wheel are made fine, and theediameter of the ratchet-wheel is made as large as is compatible with the general design of the mechanism. Thus by reason of said fine tooth pitch, large diameter of the ratchet-wheel and large rotary displacement of the clutch, the

aliquant relation of the clutch-tooth-spacing to line-spacing of the platen is negligible, and does not impair uniformity of said linespacing.

The ratchet-wheel side of the clutch is keyed to the platen by a connecting train which includes a rotary platen driver in the formof a gear 40 which may be secured to the ratchet-wheel, as indicated in Figure 2.

To permit independent rotation of the ratchet-wheel and consequently of the platen, the pawl is normally disconnected from the ratchet-wheel, as shown in Figure 1, and be comes connected to the ratchet-wheel by and during a small initial portion of the linespace-lever advance stroke. In order to avoid reversing the platen during the reverse stroke of said lever, the pawl is preferably fully withdrawn from the ratchet-wheel by and during a small initial portion of said reverse stroke, that is to say, although the shape of the teeth of said pawl and ratchet-wheel may be such that the pawl may drag idly over the ratchet-wheel-teeth during the reverse stroke, it is desirable, in order to avoid the wear attending such dragging of the pawl, that the latter be fully withdrawn from the ratchet-wheelas the reverse stroke is begun. To this end, the pawl may be provided with an arm 42, which, as best shown in Figure 3, may be slotted to embrace a tab 43 ofra ring 44 mounted for rotation about an axis concentric with the axis about which the pawl revolves. To enable said ring 44 and its tab 43 to co-operate with the pawl to effect engagement and disengagement of the latter, said ring is frictionally controlled,

' and to this end, as best shown in Figure 9, is

retained in a friction bearing, generally indicated by the number 47.

It will be seen from Figure 1 that a small initial movement of the pawl-carrying arm '37 in line-spacing direction will cause the pawl to be rotated relatively to said arm 37 by reason of the frictional drag on the ring 44, which furnishes the necessary reaction that eifects said relative rotation of the pawl and causes it to approach and engage the ratchet-wheel in said small initial movement.

In the continued rotation of the now engaged pawl and ratchet-Wheel, the ring 44 is constrained to rotate with said pawl and ratchetwheel, and thus is, at the end of the line-space able the pawl, in its reverse stroke, to clear said ratchet-wheel and may be determined by means of a stop 41 projecting from the pawl-carrying arm 37. As said pawl-carrying arm 37 commences its reverse movement, the pawl recedes until the side of the arm 42 thereof strikes said stop 41. By reason of the frictional drag on the ring 44, the pawl is held against said stop throughout said reverse movement, and it will be apparent that said pawl remains disengaged after the reverse movement is terminated, so that the ratchet-wheel may be free to be rotated in any direction for independent rotation of the platen.

A feature of the invention conducing to compactness of the mechanism, and other advantages, is the organization of the parts, whereby the clutch, that is to say the pawlarm and ratchet-wheel, are mounted concentrically with the line-space-lever fulcrum. A stud, generally indicated by the number 45, may serve as a journal, around which the clutch and platen-driving gear 40 may freely rotate and may also serve as a fulcrum for the line-space lever 25.

The line-space lever 25, the clutch, platendriving gear 40, and the other connections between said lever and driving-gear, may be organized and assembled in a compact and complete unit ready for use, which may be secured to the letter-feeding carriage-frame.

One form of a mounting suitable for the parts of such a unit is shown in detail in Figures 10 and 12, and may consist of an upper plate generally-designated by the number 48, which may rest upon suitable seats 49 of the carriage-frame 23, and may be secured to the latter by screws 50. The mounting generally indicated by the number 46 carries the clutch and line-space-lever stud 45, which stud, for compacting the mechanism, may be lowered and hence may project from a lowered portion of the mounting. Said lowered portion may be a plate 51 spaced from the plate 48 by studs 52 which may also serve to fasten said plates 48 and 51 together, as indicated in Fig ure 12. The upper plate 48 may also carry a fulcrum stud 53 for the gear-sector 35,

The platen driver or gear 40 of the organization, supported by the carriage, frame 23 and rotated through a substantially larger degree of rotation than the required linespace rotation of the platen, may drive the platen through a reducing gear-train. Said train may include a gear 55 meshing with said gear 40, and compounded with a bevel pinion 56 meshing with and driving a bevel gear 57, the latter gear being keyed to the platen-axle 21. The gear 55 and bevel pine ion 56 may be secured one to the other and key-ed to a spindle 58 which extends vertically or parallel to the axis of the gear 40, and is journ-aled in a mounting generally indicated by the number 6.0.

The reducing gear-train from the gear to the platen-axle 21 is retained and secured in proper operating position by said mounting, said gear-train and mounting moving up and down with the platen-frame during case shifting. In order that the gear may be in mesh with the gear 40, irrespective of 'the case-shift position of the platen-frame,

the gear to may be elongated, as indicated in FiguresQ and 4. Figure 2 shows the relative positions of the gear 55 on the platen-frame and the platen-driving gear 40 onthe carriage 23 when the platen-frame is in lower-case po-.

sition. In Figure 4: the relative positions of the gear .55 and gear 40, when the platenframe is in upper-case position, are indicated by the full lines representing said gear .55, the lower-case position of said gear 55 being represented by dot-.and-dash lines in said Figure 4. In Figure 4 other parts of the platen-frame are shown. in upper-case and lower-case positions, respectively, by fulllines and dot-and-dash lines, as is clearly evident.

Because rotation of the platen as derived from operation of the line=spacing mechaanism is variable, the teeth of the pawl and ratchet-wheel will not always be in alignment for direct engagement. It is for this reason that the ratchet-wheel and pawl move through the aforesaid greater rotation as compared with the rotation of the line-space lever and the required line-space'rotation of theplaten, and it will be evident that by reason of this greater rotation thecomparatively large diameter of the ratchet-wheel and the fineness of the ratchet-wheel and pawl teeth, that'the effect of the aliquant relation be tween the line-spacing and the spacing of the clutch-teeth is negligible, and hence does not practically impair the uniformity of the linespacing.

R w ll be een hat i ta es comparatively little efiort to rotate the platen when said effort is applied at the teeth of the gear 55, in? asmuch as due to the ratio of the reducing train of which said gear 55 forms a part, the teeth of said gear 55 have a large displacement as compared with the displacement of the platen eiiected by rotating said gear 55. Thus the mechanism on the carriage-frame, as the platen-driving gear 40 thereof rotates the gear 55, reacts with very little force upon the platen-frame and the platen-frame is therefore not subjected to any undue twisting strain, nor does the platen-rotating effort, applied at the teeth of the gear 55, tend to dislodge the platen-frame from its bearings or supports. Moreover, the direction in which the efiort to rotate the gear 55 is applied is substantially longitudinal of-theplaten. An effort applied in such direction has the least tendency totwist or dislo dge the pl-aLen-f-rame because the bearings or supports for the plat.- e -frame are usually at the-ends thereof, and,

- thus spread apart in respect to the direction of said effort, afford more stable reaction than if said efiort were to be applied transversely of the platen and its line of bearings.

The pin 31, which forms one extremity of the variable platen-driving arm of the linespace lever, may be shifted to vary the length not be disturbed. To retain said cam-groovemember 62, and at the same time fur ish an adequate extent of bearing of the line-siace lever upon its fulcrum-stud 45, there maybe secured to said levera sleeve or hub 63, hav ing a hole which fits a reduced portion 64 0f said stud 45, said portion being reduced to afford shoulder 65 upon which flange 66 of said sleeve may rest to support the linespacc lever at the proper level, and definitely separate it from the pawl-carrying arm 37 and the pinion 36 secured thereto. Said pawl-carrying arm may be fitted over a hub 67 of said pinion, and may be keyed to the pinion by a dowel68, Figure 2, said hub also serving to space said arm and pinion in proper relation to associated parts of the mechanism, and to this end, may rest upon the upper surface oi": the friction-bearing 47 which retains the pawl-controlling friction ring 44.

For retaining thecamwgrooyc-member 62, and also for all ording an annular space in which a line-space-lever retracting-spring 69 may be placed, the line-space-lever sleeve 63 may be provided, at a point slightly below the top of the.-cam-groove-member 62;, w tlra flange 70 which its a central hole Tl of sa d cam-groove-membe1' so that the sides ofsaid hole and of the sleeve may afford said annular space, as is indicated in Figure 2. The end portion of said sleeve 68 may be threaded tor a clamping nut 72 whereby the cam-groovemember 62 may be secured in any of its ad.- justed positions. The cam-grcore-member 62 may be spaced at the proper level above A the top surface of the stamping 26 by tabs 73, preferably three in number,projectingupwardlyfrom said stamping, said tabs being located to support the cam-groove-merm ber ear the outer rim of the latter, n;

order to clear the cam-groove and to co-operate most efiiciently with the clamping nut- 72 in holding said cam-groove-member.

For convenience of adjusting the tension of the line-space-lever retracting-spring 69, the flange may be provided with several notches 74, in any one of which the upper end 75 of the spring 69 may be held and retained. The spring 69 may be provided at its lower end with an outwardly-extended portion 76 to react against the upper end of a stud 77 secured to, and projecting upwardly from, the plate 48 of the mounting 46 which supports the mechanism. Said stud 77 may have a groove 78 to retain the spring endportion 76. The upper end of the line-spacelever fulcrum-stud 45 may be threaded to re ceive a lever-retaining screw 80, the head of which may overlap the diameter of the sleeve 63 to serve as a stop for preventing undue loosening of the clamping nut 72, the top of the stud 45 extending sufiiciently above the top of the sleeve 63 so that the head of said screw 80 does not bind upon said sleeve.

The friction-bearing 47, which retains the pawl-controlling ring 44, may be secured by being forced over a portion 81 of the stud 45 upon which the pawl-arm 37 and its pinion 36 rotate, and may be seated against a shoulder 82 of said stud 45 formed by an enlarged portion 83 of the latter, Figures 9 and 12, said enlarged portion 83 terminating at its lower end in a flange 84, the upper shoulder of which may form a convenient seat for the rotary platen driver or gear 40, journaled upon said enlarged portion 83. The frictionbearing 47 may be pressed over the portion 81 of the stud after the gear 40 and ratchetwheel 39 are in place.

For pivotally supporting the ratchet wheel-pawl 38, the pawl-carrying arm 37 may be provided with a pivot-stud 86 projecting downwardly from said arm 37, as indicated in Figure 2. Said stud 86 may have a flange 87 to afford adequate seating against the arm 37 and to space the pawl 38 from said arm as indicated. The pawl may be retained upon the stud 86 by means of a washer 88, which may be riveted over the lower end of the stud as indicated.

For rotation about its stud 53, the gearsector 35 may have a hub 90, the lower end of which may bear upon a flange 91 of said stud 53. Said sector 35 may be retained by a screw 92 threaded into the upper end of the stud 53.

The link 32, whereby the sector 35 is connected to the line-space lever 25, may be formed with a crook, as shown, to clear the adjacent cam-groove-member supporting tab 73 when the mechanism is at its extreme operated position, as indicated in Figure 3. Said link'32 may be flat, and in order to secure the sector end thereof at the proper level, said end may be pivotally connected to a stud 93 Secured to, and projecting upwardly from, the sector-arm 34. Said stud may be shouldered at its upper end to afford a pivot for said link which may be retained by a screw 94. The line-space-lever end of the link may be retained in the space formed between the top of the slide 30 and the bottom of the camgroove-rnember 62, as indicated in Figure 2, said space being determined by the height of the cam-supporting tabs 73.

It will be apparent that for any given movement of the line-space lever 25, the resulting movement of the rotary platen driver or gear 40. and hence the platen 20, may be varied, said movement of said gear and platen depending upon the distance of the pin 31 from the line-space-lever fulcrum, which distance in turn depends upon the adjustment ofthe cam-groove-member 62. By providing for different throws of the lever 25, different multiples of the line-space unit or basis established by the position ofthe pin 31 may be effected. For reasons which will presently become apparent, the line-space-efi'ecting stroke of said lever 25 is always terminated with said lever in the same position. Consequently, for effecting difierent throws of the lever for different line-space multiples, the initial position of the lever 25 is varied according to the multiples desired.

Novel means whereby the initial position of the lever 25 is determined will. now be clescribed. A .line-space-lever stop-arm, generally indicated by a number 96, may be fulcrumed around the lower end of the linespace-lever stud 45, so that a line-space leverarresting abutment 97, forming part of said arm, may. in different positions of said arm. arrest said lever in different positions. Said abutment 97 may, as indicated, project upwardly from the forward]y-extending portion 98 of said arm to engage the side of the line-space lever. Said forwardlv-extending stop-arm portion 98-mav underlie the linespace-lever part 27 and be somewhat separated therefrom, as indicated, by a space 99. The fulcrum end 100 of said stop-arm maybe bent downwardly from the forwardly-extending portion 98, as indicated, in order that it may be fulcrumed about the lower end of the fulcrum-stud 45. The stop-arm 96 may be fulcrumed upon the portion 101 of said stud 45 included between the flange 84 and the surface of the plate 51 from which-said stud 45 projects. For holding the stop-arm 96 in its different positions there may be provided notches 102 into which a projection 103 of the stop-arm 96 maybe set, as best indicated in Figures 2 and 7. Said notches 102 may be formed in a segment 104, which may be secured as by screws 105 (Figure 10) to the upper surfa e of the plate 48 of the mounting 46. Said notches'102 are formed in the upper surface of said sector, which upper suri'io face also supports the forward stop-arm portion 98 at the proper level.

By raising the stop-arm by its forwardlyextending portion 98, the projection 103 will be lifted clear'of the segment 104, and while said portion 98 is thus raised the stop-arm may be shifted to any position. Figure 8 indicates how the stop-arm portion 98 may be thus lifted, the stop-arm 96 tending to tilt as a whole about a portion close to the fulcrum-stud 45, as indicated, and about another portion 106, with which the stop-arm may be provided to secure stability of said arm in any of its set positions. Tosecure said stability, said portion 106 may be retained between the top and bottom sides of a groove 107 which may be formed in the segment 104:. Said stabilizing portion 106 of the stop-arm 96 may be formed at the end of a lateral extension 109, which may be bent downwardly. from the stop-arm portion 98, to align said portion 106 with its retaining groove 107.

To assist in retaining the stop-arm in any of its stop positions, there may be provided a spring 110 which may be secured'to the bottom of the extension 109, as by rivets 111 (Figure 3). Said spring 110 may be provided with an end portion 112, which may enterthe groove 107, and the spring may be sprung so that said end portion 112, at all times, presses against the upper side of said groove 107, and by the reaction thus aflorded thespring 110 tends to hold the forward stoparm portion 98 against the locating segment 104-. The space 99 between the stop-arm portion need only be sufficient to enable the stoparm holding projection 103 to be lifted clear of the segment 104:. When the stop-arm is to be shifted, both the line-space lever and the'stop-arm are grasped between the fingers, and the forward stop-arm portion 98 is drawn upwardly toward the line-space lever to clear the segment preparatory to shifting both the stop-arm 98 and the line-space lever to thenew position. The stop-arm may then be-re'leased so that the stop-arm projection 103 may settle into the proper slot 102, such settling of the projection into the slot being facilitated by the spring 110. The

portion 106 operates to stabilize the stop-arm in any of its different positions, by resisting the tendency of the stop-arm to turn over about the base of the stop-abutment 97 and 3 lift the'projeetion 103 out of the slot 102 as the line-space lever bears against said stop-abutmerit.

The'line-space stroke of the lever may be terminated with said lever always in the same position, by means of a fixed stop 113, which may be secured to and may project above the segment 10 1, so that the side of the line space lever 25 may, at the end of the linespa'ce'stroke, strike said stop.113,'as indicated in Figure 3.

The stud 45, which affords the line-spacelever fulcrum and alsorattords other fulcrums for the mechanism, as explained, may be secured to the plate 51, fromwhich it projects, by a screw 115, Figures 10 and 12. The lower end of-said stud may terminate ina portion which will not only arrest'thepawlat a defi- Y nite point at the end'of the line-space stroke,

but will also force the pawl against the ratchet wheel to cause :the pawl and ratchetwheel to interlock and'thereby positively hold the ratchetevheel 3 9 asthe pawl is arrested. For thus arresting the pawland forcing it to interlock with the ratchet-whee'hthe stud 77, against which the line-space lever retracting-spring '69 reacts, may be utilized, and may serve to arrest the .pawlin the manner indicated in Figures 3 and l. 'It will be apparent from Figure '3 that the stud 77 may be located so as to force the teeth of the pawl and ratchet-wheel togetheras the :pawl iszarrested'by said stud. The interlocking or forcing together of the pawl and ratchet-wheel teeth may be facilitated by providing the end of'the pawl with'a suitably inclined camming surface 118 to-bear'against the stud 77. For'determining the exact point at :which the movement of'the ratchet-wheel 39 is thus arrested "by the stud 77, there may be provision for' adjustment of said stud along the path ofthepawl'38. To-this'end,a'h0le-119 in the mechanism-mounting plate 48 maybe elongated, a screw 120 passing throughsaid hole to secure said stud. As the movement of the 'pa-wland ratchet-wheel isiarrested by a'fixed stop, namely, the stud 77, and the linespace'stroke of the lever 25 istalso arrested by the fixed stop 113, the slot 29, wherein the slide 'is guided for varying the lengthof the platen-driving arm ofthe line-space lever, must be'concentric with'the pointat which the link 32 is pivoted to the gear-sector 35. That is to say, said slot .29 must be cencentric with said point when the mechanism is in a position corresponding to Figure 3. m which the line-space lever is at the end of its line-space stroke. It will be 'seen'that the slot 29 being thus concentric with the point 33,the slide 30 maybe moved 'tozany position while at the same'time the pawl 38 mavalways'be arrestedby the stud 77.

Suitable details of the friction bearing 47 that retains the pawl-controlling ring 44 are illustrated in Figure 9, which includes a cross-sectional view "of the assembled bearing and detail perspective views of the bearing and the ring 44. The bearing 47 may include a ring 121 having a shoulder 122 which may be overlapped by a ring 123; said rings being fastened together as by riveting a projection 124 from said shoulder over the edge of the central hole of said ring 123.

Thus there may be formed between said ring 123 and another shoulder 125 of the ring 121 the sides of groove which has as its bottom the portion projecting from said shoulder 125. Said bottom of the groove may fit the central hole 126 of the ring 44 to retain the same concentrically with the central hole 127 formed in the ring 1210f the hearing. The ring 44 may be formed'of thin material, as, for example, spring steel of a thickness not greater than the width of the groove in which said ring 44 is retained. The required frictional drag upon the ring 44 maybe effected by warping, twisting or bending the ring, as suggested by the dot-'and-dash lines 128, so that when said ring is assembled and pressed fiat between the'sides of the groove the tendency of the ring to warp again will cause the ring to rub against the sides of the groove to create the desired friction. For holding the as sembled friction bearing in place, the central hole 127 may be a force fit over the stud 45at the portion 81 of said stud.

If, for compactness of the mechanism, the rotaryp'laten driver or gear 40 is lowered so that the portion of said gear, which engages the gear in normal case position of the platen, is below the pitch line of the bevel gear' 57, the central portion 129 of said gear 55 may be elevated above said pitch line to'afford room for the bevel pinion 56.

Figuresll and 13 illustrate details of the speed-reducing train that connects the platen-driving gear 40, mounted on the typewriter-carriage, to the platen 20 carried in the platen support or case-shifting frame 22. The speed-reducing train and its mounting are the only parts of the line-space organization carried by the platen-support, and the mounting may be arranged to hold the'parts of the speed-reducing train in proper juxtaposition to one another, and also to secure proper engagement of said train with the platen-driving gear 40 on the letterteeding carriage. To this end, said mounting may include spacedapart ears 130 which may fit over the platen-axle 21, so that the location of said mounting and speed-reducing train may thereby be definitely keyed to'th'e platen-axle. Said ears 130 may extend "downwardly from front-to-rear-extending cross-members 131 and 132, which may be joined by members 133 extending parallel to the platen-axle. The cross-member 132, toward the platen support, may be formed in two parts, as best shown in Figure 13, one part having one of the ears 130 and also having an extension 134 projecting toward the platen-support, the other part being formed by bending the member 133", which, in turn, is formed by bending the cross-member 131. The opposite member is also formed by bending the crossmember 131. From said othcrpart of the cross-member 132 there may be bent a portion 135 to afford a bearing hole 136 for the lower end of the spindle 58. Said spindle ganization carried by the platen support, may have an upper bearing in a member 137, which, in order to be assembled as part of the mounting, may be extended to fornrportions 138 bent around the gear 55, so that its ends may be secured to the cross-members 131 and 132 of the mounting in the manner indicated in Figure 13. The frame-like structure thus to med by the member 137 and its extensions also serves to brace the cross-members 131 and 132 againstv spreading or contracting The bevel 57 may have projecting from the tooth-face side thereof a hub 141, and from the opposite side a hub 142, and the ears 130 of the mounting 60 may straddle the opposite ends of the gear-hubs 141 and 142, as indicated in Figure 11, to thereby serve in locating the in unting 6O longitudinally of the platen-axle. Said gear 57 may be keyed to the platen-axle 21, as by one or more set screws 143. There may also be provided collars 144 and 145 against which the outer sides of said ears may bear. The collar 144 may be keyed to the platen-axle, as indicated in Fig are 11, while the collar 145 may constitute the bearing in which the platen-axle is journaled. The extension 134 which projects towards the platen-support is for anchoring the mounting to said platen-support, and may be, to this end, provided with an car 146 through which may pass a screw 147, for se curing the mounting to a stud 148 projecting from the side of the platen-frame or support 22. In the illustrated form of the mounting 60 the several membersthereof are formed of sheet-metal whose parts may be fastened together, as for example, by rivets 149. For insuring that the bevel gear 57 and bevel pinion 56 may at all times be held close enough to one another to avoid back lash, there may be provided a backing for said gear 57 which may brace said gear at a point opposite the bevel pinion 56. Said backing may be in the form of a block 150 which may bear against the back of the bevel gear 57 and thus aid in resisting any tendency of the reaction between said gear 57 and bevel pinion 56 to thrust the gear 57 away from said pinion 5G. The block 150 may also serve as a brake upon the platen to minimize the tendency to accidental displacement of the platen. To this end, said block 150 may bear with a suitable degree of friction upon the back of the gear 57.

A hole 152, through which the screw 147 passes to secure the mounting 60 to the platenframe 22, may be elongated, as indicated in Figure 13, so that the mounting may bcl'ocked about the platen-axle to thereby bring the gear 55 into proper mesh with the platendriving gear 40 of the letter-feeding carriage. For direct rotation of the platen by hand, a usual platen-rotating knob 153 may be secured to the end of the platen-axle beyond the line-spacing mechanism.

The plate 48 of the mounting 46 for the line-spacing mechanism on the carriage may be opened out around the fulcrum-stud 45, as indicated at 154, so as to clear the gears 40 and 55 and afford clearance for the multiplespace stop-arm 96 and the shifting of said stop-arm. The line-spacing mechanism supported by said mounting may be covered by a casing, generally indicated by the number 155, which may be arranged to expose only the cam-groove-member 62, and the handle portion of the line-space-lever part 27. A fingerpiece 156 of the multiple-space stop-arm 96 may project beyond said casing for manipulation of said stop-arm 96.

For convenience of assembling the mechanism, the casing 155 may be formed in two parts, a lower part 157 and an upper part 158. Said lower part of the casing may be in the form of a wall falling below and rising above the plate 48, as indicated, and reaching around said plate almost to the periphery of the ear 55, see Figure 10. Said lower part 157 of the casing may be secured to the plate 48, as by solder applied around the'joint between said part 157 and the plate 48, as indicated at 159, Figure 12. Upon the upper edge of said lower part 157 of the casing, the upper part 158 of the casing may rest, the outline of said upper part, as viewed from the top of the casing, coinciding with the outline of the lower part. The upper part may include side portions 160 forming said outline, and a mechanism-covering top-portion 161 having an opening to clear the cam-groove-member 62.

The stop-arm segment 104 may have a number of slots 102 to position the stop-arm 96 for different multiples of line spacing, for example as shown herein, a single linespace, and multiples of 1 1 2, 2 and 3 times said single line space, it being understood that while the multiples might not be exact for all positions of the pin 31, the .locations of the slots may be arranged, if desired, to secure a mean of the variations from exact multiples for different positions of the pin 31, and that thus said multiples may be exact enough for practical purposes.

The upper part 158 of the casing 155 may be secured by screws 166 which may be threaded into the plate 48, as indicated in Figures 5 and 6.

The cam-groove-member 62 and the clamping nut 72 therefor, may be provided with knurled finger-surfaces as shown at 167. The cam-groove-member 62 may also be provided with graduations 168 spaced with any desired degree of fineness and cooperating with a pointer which may be a mark 169 on the casing to serve as an index of the line spacing corresponding to the adjustment of said cam-member, it being understood that the reading isto be taken when the line-space lever abuts the stop 113. The side of the upper part 158 of the casing may have an opening 170 to clear the gear-sector 35 and the stamping 26 of the line-space lever, as indicated at Figure 3.

For clearing the handle portion of the line-space lever, the front of the upper part 158 of the casing 155 may have an opening 163 extended sufficiently around said front to accommodate the swing of the line-space lever. Along the upper edge of said opening there may be markings 164 spaced according to the different positions of the line-space lever corresponding to the diflerent line-space multiples. Said markings may co-operate with a pointer 165 on the line-space lever to indicate the line-space multiple for which the mechanism is set. The handle portion of the line-space lever may have at the end thereof, as indicated in Figures 5 and 6, a finger-piece 162. j

A casing may also be provided to enclose the speed-reducing train carried by the platen-support or frame 22, said casing being generally indicated by the number 171 and consisting of a top portion 17 2 and sides which may surround and cover the gear 55, the portion of the sides surrounding said gear being indicated at 173. The top portion and T side of the casing may be cut away, as indicated at 174, Figure 5, to clear the casing 155 on the carriage sufficiently to accommodate the case-shifting movement of the platen and its support or frame. Said speed-reducing train-casing 171 may be secured by screws '17 5 which may pass through the top portion 172 of the casing and be threaded into the platen-frame member 22, as indicated in Figures 5 and 6. The spindle 58 to which is keyed the bevel pinion 56 may project through an opening 176 to a point where a finger-knob 177 attached to said spindle is conveniently accessible. Said finger-knob may, by enabling the spindle 58 to be rotated thereby, be used for fine adjustment of the work-sheet on the platen to the printing line, said fine adjustment being effected by reason of the relatively large displacement of the spindle 58 as compared with a corresponding displacement of the platen. The top portion 172 of the casing 171 may be elevated at a. portion 179 (Figures 5 and6)' so that said latter portion may overlie and clear the gearsector 35 and permit up-and-down case-shifting movement of said casing 171. To also clear the end of said sector 35, the side of the casing 171 may be flared out as at 180 (see Figures 3 and 5).

The flange of the line-space-lever fulcram-sleeve 63 may be a separate piece having a thread which fits the clamping nut thread of said sleeve. The lower flange 66 of said sleeve may be cut away where it would otherwise overlap the sides of the slide-guiding slot 29 in the line-space-lever stamping 2'0 which is seated against said lower flange. The sleeve 63 and stamping26 are of course fastened together, as by solder or riveting not shown.

After the line-space-lever retractingspring 69'is in place around the fulcrumsleeve 63 of said lever, the flange 70 of said sleeve may be threaded over the upper sleeve end to the proper level above the line-spacelever stamping 26, and secured against turning about said sleeve, as by solder, staking, or a he It vvill be noted that in the improved mechanism all the controlling parts, that is to say, all the parts which control the extent of movement of the rotary platen-driver or gear 40, are, including said gear 40, solidly supported by the letter-feeding carriage. Hence such controlling parts cannot be relatively displaced, nor, therefore, can they cause binding or lost motion as they resist the reactions set up in the operation of the mechanism. The points, about which the several controlling parts of the mechanism operate, are always maintained in proper relation to one another, and it is apparent that such might not be the case if such of the controlling parts as, for example, the equivalent of the platen-driving gear 40, the clutch and clutch-controlling mechanism, were carried by the shiftable platen-support which might be none too rigidly mounted, as often occurs in conventional typewriter-design.

Although the parts carried by the letterfeeding carriage are preferably assembled as a unit which may readily be attached to, or removed from, said carriage, as herein illustrated and described, it will be understood of course that instead of supporting said parts in a mounting 46, the mounting 46, and hence the unitary feature of the assembly, may be dispensed with, in which case the carriageframe '23 itself may serve as such mounting, suitable provision being accordingly made-in the form of the carriage-frame for the direct attachment thereto of those parts herein shown attached to the mounting 46.

As an illustration of different adjustments of the mechanism for difierent extents of line-spacing, reference may be had to Figures 1, 3 and 5. Figures 1 and 3 show the mechanism as adjusted for line space of maximum extent; that is to say, the grooved cam-member 62 (not shown in Figures 1 and will have been turned to bring the pin 31 to its farthest distance from the linespace lever-fulcrum, the multiple space stoparm 96 being set, as best shown in Figure 3, in the farthest notch 102 from the fixed stop of the mechanism, represents that the camgroove-member 62 has been turned so that the pin 31 is at its mlnimum distance from the line-space lever-fulcrum, and that the stop-arm 96 is set in the notch corresponding to double spacing. It will be obvious that for each position of the stop-arm 96, the pin 31 may be micrometrically adjusted to any position within its range of movement by turning the grooved cam-member 62. Vice versa, regardless of the position of the pin 31, the stop-arm may be set into any of the notches 102. Thus the line-space extent may be micrometrically varied from a minimum of say one-tenth of an inch,which minimum would correspond to an adjustment of the stop-arm 96, to the single-space notch, and of the pin 31 to its minimum distance from the line-space lever-fulcrumto a maximum of say six-tenths of an inch, said maximum corresponding to the adjustment of the mechanism, as shown in Figures 1 and 3.

It will also be noticed that the line-spacing mechanism on the letter-feeding carriage is compactly arranged, and that the arrangement of the rotary platen-driver, clutch, clutch-controlling mechanism and line-space lever, all to operate about one fulcrum-stud, conduces to said compact arrangement.

It will be noted that the attachment may include two separate preassembled units, as

155 and 171, one unit 171 secured to the platcn-shift-frame and the other unit 155 secured to the carriage, the two units becoming co-operative by the bringing together of the two gears 410 and 55 for a concomitant train of mechanism intermediate the line-space lever and the platen.

Variations may be resorted to within the scope of the invention, and portions of the improvements maybe used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination with a revoluble platen. a letter-feeding carriage and a shiftable platen-support carried by said carriage and shiftable relatively thereto for case shifting, of a reciprocatory line-space lever fulcrumed on said carriage, a platen-driving-gear rotatably mounted on said carriage, means for rotating said gear carried by said carriage and solidly supported thereon, said gear-rotating means controlled by the line-space lever movement and having means so as to be effective to rotate said gear only in one direction of said lever-movement and ineffective in the reverse direction, and means, carried by the platen support, connecting said gear and platen to effect line-spacing of the latter through rotation of said gear, said last-mentioned con necting means on the platen-support and the gearon the letter-feeding carriage having provision so as to be relatively shiftable in accordance with the case-shifting movement of the platen and its support. a

2. In a typewriting machine, the combination with a revoluble platen, a letter-feeding carriage and a shiftable platen-support carried by saidcarriage and shiftable relatively thereto for case-shifting, of a reciprocatory line-space lever fulcrumed on said carriage, a platen-driving-gear rotatably mounted on said carriage, means for rotating said gear carried by said carriage and solidly supported thereon, said gear-rotating means controlled by the line-space lever movement and having means so as to be effective to rotate said gear only in one direction of said levermovement and ineffective in the reverse direction, and means, carried by the platensupport, connecting said gear and platen to effect line-spacing of the latter through rotation of said gear, said gear-rotating means also having provision to permit independent rotation of the platen in any direction.

3. In a typewriting machine, the combination with a revoluble platen, a letter-feeding carriage and a shittable platen-support carried by said carriage and shiftable relatively thereto for case shifting, of a reciprocatory line-space lever fulcrumed on said carriage, a platen-driving-gear rotatably mounted on said carriage, means for rotating said gear carried by said carriage and solidly supported thereon, said gear-rotating means controlled by the line-space lever movement and having means so as to be effective to rotate said gear only in one direction of said levermovement and inefiective in the reverse direction, settable means for limiting the disilacement of the gear-rotating means to different extents for diil'erent line-space multiples, and means, or 'ried by the platen-support, connecting said gear and platen to effect line spacing of the latter through rotation of said gear.

4. In a typewriting machine, the combination with a revoluble platen, a letter-feeding carriage and a shiftable platen-support carried by said carriage and shiftable relatively thereto for case shifting, of a reciprocatory line-space lever fulcrumed on said carriage, a platen-driving gear rotatably mounted on said carriage, means for rotating said gear carried by said carriage and solidly supported thereon, said gear-rotating means controlled by the line-space lever movement and having means so as to be effective to rotate said gear only in one direction of said lever-movement and inefi'ective in the reverse direction, said gear-rotating means also having provision whereby the extent of rotation of said gear, as derived from a given movement of said lever, may be micrometrically varied at will, and means, carried by the platen-support, connecting said gear and platen to effect line-spacing of the latter through the rotation of said gear.

5. In a typewriting machine, the combination with a revoluble platen, a letter-feeding carriage and a shift-able platen-support carried by said carriage and shiftable relatively thereto for case shifting, of a reciprocatory line-space lever fulcrumed on saidcarriage,a platen-driving-gear rotatably mounted on said carriage, means for rotating said gear carried by said carriage and solidly support ed thereon, said gear-rotating means controlled by the line-space lever movement and having means so as to be effective to rotate said gear only in one direction of said levermovement and ineffective in the reverse direction, said gearrotating means also having provision whereby the extent of rotation of said gear, as derived from a given movement of said lever, may be micrometrically varied, at will, and means, carried by the platen-support, connecting said gear and platen to effect line spacing of the latter through the rotation of said gear, said last mentioned connecting means on the platensnpport and the gear on the letter-feeding carriage having provision so as to be relatively shiftable inaccordance with the caseshifting movement of the platen and its support.

6. In a line-spacing mechanism for a revoluble typewriter-platen having a caseshitting platen-support carried by a lettereeding carriage, the combination with a reciprocatory line-space lever mounted on said carriage, of a rotary platen-driver mounted on said carriage, means carried by said carriage whereby reciprocation of said lever causes unidirectional line-space-efi ecting r0- tation of said driver, said means including provision whereby the extent of rotation of said driver is substantially greater than'the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speedreducing device carried by the platen-support, whereby the large rotation of said driver is translated into platen-rotation of line-space extent.

'4'. In a line-spacing mechanism for a revoluble typewriter-platen, the combination ith a letter-feeding carriage, a platenniounting, and spaced-apart platen-supports for said mounting carried by said carriage and movable for case-shifting, of a reciprocatory line-space operator mounted on said carriage, a rotary platen-driver mounted on said carriage, means carried by said carriage whereby reciprocation of said operator causes uni-directional line-space-eflecting rotation of said driver, and a device carried by said platen-mounting, whereby said driver may rotate said platen for line spacing, said device and driver being arranged so that the force of reaction between them, as the platen is rotated, is substantially in a direction in which said mounting-supports are spaced apart.

8. In a line-spacing mechanism for a revoluble typewriter-platen, the combination with a letter-feeding carriage, a platenmounting, and spaced-apart platen-supports for said mounting carried by said carriage and movable for case-shifting, of a recipro- "atory line-space operator mounted on said carriage, a rotary platen-driver mounted on said carriage, means carried by said carriage whereby reciprocation of said operator causes uni-directional line-space-eflecting rotation of said driver, said means including provision whereby the extent of rotation of said driver is substantially greater than the required platen-rotation to thereby minimize the force with which said driver may react upon said mounting, and a speed-reducing device, carried by the platen mounting, whereby the large rotation of said driver is translated into platen-rotation of line-space extent, said device and driver being arranged so that said force is substantially in the direction in which said mounting-supports are spaced apart.

9. A line-space mechanism for a typewriting machine, having a carriage and a shiftable platen-frame, said mechanism including two separate preassembled units, one unit secured to the platen-frame and including a train of gearing connected with the platen and beginning with a driven gear, and the other preassembled unit secured to the carriage and including a train of gearing beginning with a line-space lever and ending with a driving gear, the attachment of the two units to the carriage and platen-frame respectively bringing the driving gear of one train into engagement with the driven gear of the other train, for a concomitant translation of motion intermediate the line-space lever and the platen.

10. A line-space mechanism for a typewriting machine having a carriage and a shiftable platen-frame, said mechanism including two separate preassembled units, one unit secured to the platen-frame and including a train of reduction gearing connected with the platen and beginning with a driven gear, and the other preassembled unit secured to the carriageand including a train of multiplying gearing beginning with a line-space lever and ending with a driving gear, the attachment of the two units to the carriage and platenframe respectively bringing the drivin gear of one train into engagement with the driven gear of the other train, for a concomitant translation of motion intermediate the linespace lever and the platen.

11. In a line-spacing mechanism for a revoluble typewriter-platen having a case-shitting platen-support carried by a letter-feeding carriage, the combination with a reciprocatory line-space lever mounted on said carriage and having a shiftable device forming a platen-driving arm whose length may be va ied, of a rotary platen-driver mounted on said carriage, means carried by said carriage and connecting the variable platenlevcr arm to said driver, whereby reciprocation of said lever causes uni-directional linespace-etiecting rotation of said driver, said means including provision whereby the extent of rotation of said driver is substantially greater than the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speed-reducing device carried by the platen-support, whereby the large rotation of said driver is translated into platen-rota tion ofline-space extent.

12. In a line-spacing mechanism for a revoluble typewriter-platen having a case-shifting platen-support carried by a letter-feeding carriage, the combination with a reciprocatory line-space lever mounted on said carriage, of a rotary platen-driver mounted on said carriage, means whereby the reciprocation of said lever causes uni-directional linespace-effecting rotation of said driver, said means including a reciprocatory gear-sector having an arm operatively connected to an arm of said lever, a pinion operatively connected to said sector and to said driver, said sector and pinion proportioned to effect greater rotation of said driver than the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speed-reducing device carried by the platen-support, whereby the large rotation of said driver is translated into platen-rotation of line-space extent.

13. In a line-spacing mechanism for a revoluble typewriter-platen having a caseshifting platen-support carried by a letterfeeding carriage, the combination with a reciprocatory line-space lever mounted on said carriage, of a rotary platen-driver mounted on said carriage, means whereby the reciprocation of said lever causes uni-directional line-space-eflecting rotation of said driver, said means including a reciprocatory gear-sector having an arm operatively connected to an arm of said lever, a pinion operatively connected to said sector and to said driver, said sector and pinion proportioned to effect greater rotation of said driver than the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, means whereby the relative length of said arms may be varied, at will, to thereby change the extent of rotation of the driver as derived from a given movement of said lever, and a speedreducing device carried by the platensupport, whereby the greater rotation of said driver is translated into platen-rotation of line-space extent.

14 In a line-spacing mechanism for a revoluble typewriter-platen having a caseshifting platen-support carried by a letterfeeding carriage, the combination with a reciprocatory line-space lever, of a fulcrum for said lever fixedly mounted on said carriage, a rotary platen-driver arranged, for compactness of the mechanism, to rotate about the axis of said fulcrum, means, carried by said carriage, connecting said lever to said driver whereby reciprocation of said lever causes uni-directional line-space-eifecting rotation of said driver, said means ineluding provision whereby the extent of rotation of said driver is substantially greater than the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speed-reducing device carried by the platensupport, whereby the large rotation of said driver is translated into platen-rotation of line-space extent.

15. In a line-spacing mechanism for a revoluble typewriter-olaten having a caseshifting platen-support carried by a letterfeeding carriage, the combination with a reciprocatory line-space lever, of a fulcrum for said lever fixedly mounted on said carriage, a rotary platen-driver arranged, for compactness of the mechanism, to rotate about the axis of said fulcrum, means carried by said carriage, connecting said lever to said driver whereby reciprocation of said lever causes uni-directional line-space-efiecting rotation of said driver, said means including a reciprocatory gear-sector operatively connected to said lever, a pinion operatively connected to said sector and driver, said sector and driver proportioned to effect greater rotation of said driver than the required platen-rotation, to thereby minimize the force with which saiddriver may react upon said platen-support, and a speed-reducing device carried by the platen-support, whereby the large rotation of said driver is translated into platen-rotation of line-space ex tent.

16. In a line-spacing mechanism for a revoluble typewriter-platen having a caseshifting platen-support carried by a letterfeeding carriage, the combination with a reciprocatory line-space lever, of a fulcrum for said lever fixedly mounted on said carriage, a rotary platen-driverarranged, for compactness of the mechanism, to rotate about the axis of said fulcrum, means, carried by said carriage, connecting said lever to said driver, whereby reciprocation of said lever causes uni-directional line-space-eifect ing rotation of. said driver, said connecting means including a reciprocatory gear-sector operatively connected to said lever, a fulcrum for said gear-sector carried by said carriage and spaced from the line-space-lever fulcrum, a pinion meshing with said sectorand for compactness of the mechanism, mounted for rotation about the line-space-lever fulcrum, said connecting means also including a clutch-device for operatively connecting said pinion and driver to effect said uni-directional rotation of the driver, said sector and pinion proportioned to efiect greater rotation of said driver than the required plat en-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speed-reducing device carried by the platen-support, whereby the large rotation of said driver is translated into platen-rotation of line-space extent.

17 'In a line-spacing mechanism for a revoluble typewriter-platen havlng a case-J to said driver, whereby reciprocation of said lever causes uniedirectional line-space-eflecting rotation of said driver, said connecting means including a reciprocatory gear-sector operatively connected to said lever, a fulcrum for said gear-sector carried by said car- I riage and spaced from the line-space-lever fulcrum, a pinion meshing with said sector and, for compactness of the mechanism,

mounted for rotation about the line-spacelever fulcrum, said connecting means also including a pawl and ratchet-wheel arranged for compactness of the mechanism, to rotate about the axis of the line-space-lever ful-' crum, said pawl and ratchet-wheel connecting said pinion and driver to effect said unidirectional rotation of the driver, said sector and pinion proportioned to effect greater rotation of said driver than the required platen-rotation, to thereby minimize the force with which said driver may react upon said platen-support, and a speed-reducing device carried by the platen-support, where-Y by the large rotation of said driver is translated into platen-rotation of line-space extent.

18. In K a line-spacing mechanism for a revoluble typewriter-platen having a caseshifting platen-support carried by a letter:

feeding carriage, the combination with-a re- I ciprocatory line-space lever having a shift abie device forming a platen-driving arm whose length may be varied, and means whereby said device'may be shifted and secured in any position, of a rotary platendriver mounted on said carriage, a connecting train carried by said carriage, connect.- ing said variable.platen-driving arm, to said driver, whereby reciprocation of said lever causes uni-directional line-space-efi'ecting rotation of said driver, and means carried by the platen-support connecting the driver to the platen.

19. In a line-spacing mechanism for a revoluble typewriter-platen having a caseshifting platen-support carried by a letterfeeding carriage, the combination with a reciprocatory line-space lever having a platen-driving arm, of a reciprocatory gear-sector having an arm operatively connected to said platen-driving arm, said sector mounted on said carriage, one of said arms having a shiftable device, whereby its effective length may be varied, to thereby change the extent of rotation of said sector as derived from a given movement of said line-space lever,

means for micrometrically varying the position of said device and securing it in any position, a rotary platen-driver mounted on said carriage, means, connecting said driver and sector, whereby reciprocation of said sector causes uni-directional line-space-effecting rotation of said driver, and means carried by the platen-support connecting the driver to the platen.

20. A universal line-spacing mechanism for a revoluble typewriter-platen having a case-shifting support carried in a letter-feeding carriage, said mechanism including a rotary platen-driver rotatable about a bear ing carried by said carriage for solid support, means carried by the platen-support, connecting said driver to said platen, and means, also carried by the carriage for solid "support, for rotating said driver step by step,

at will, to line-space the platen in successive steps of line-space extent.

21. A universal line-spacing mechanism for a revoluble typewriter-platen having a case-shifting support carried in a letter-feeding carriage, said mechanism including a rotary platen-driver rotatable about arbearing carried by said carriage for solid support, means carried by the platen-support connecting said driver to said platen, and means, also carried by the carriage for solid support, for rotating said driver step by step, at will, to line-space the platen in successive steps of line-space extent, said latter driver-rotating means having provision whereby the rotary steps of said driver are of substantially greater extent than the required platen-rotation, thereby to minimize the reaction of said driver upon said platen-support, the aforesaid means operatively connecting said driver to said platen having provision whereby the large rotation of said driver is translated into platen-rotation of line-spacing extent.

22. In a line-spacing mechanism, the combination wit-h a revoluble typewriterplaten, a carriage, a vertical fulcrum-stud on said carriage, and a reciprocatory line-space lever fulcrumed on said stud, of a rotary platen-.

driver rotatable about said studand positively geared with the platen, and a one-way clutch rotatable about said stud, said clutch having its driven member connected to said driver and its driving member connected to said line-space lever.

23. The invention as set forth in claim 22, in combination with clutch-controlling means operative to keep the driven and driving members of the clutch disengaged when the line-space lever is in its retracted position, to permit independent rotation of the platen.

24:. In a line-spacing mechanism, the combination With a. revoluble typewriter-platen, a carriage, a vertical fulcrum-stud on said carriage, and a reciprocatory line-space lever fulcrumed on said stud, of a. rotary platendriver rotatable about said. stud and positively geared with the platen, a one-way clutch rotatable about said stud, said clutch having its driven member connected to said platen-driver and to a driving member connected to said line-space lever, and sett-able means on said stud effective to limit the stroke of the line-space lever to difierent extents for different line-space multiples.

25. In a line-spacing mechanism, the combination with a revoluble typewriter-platen, a fulcrum-stud spaced apart from said platen, a reciprocatory line-space lever fulcrumed on said stud. a rotary platen-driver rotatable about said stud and geared to the platen, a one-way clutch rotatable about said stud, said clutch having its driven member connected to said driver, and means connecting the driving member of the clutch to said line-space lever, said latter connecting means including a reciprocatory sector and a fulcrum for said sector having its axis spaced from the axis of the line-space-lever-fulcrum, said sector being geared to said driving member and having an arm connected to an arm of said lever. 26. The invention as set forth in claim 25, in combination with means for varying the relative lengths of the aforesaid arms of said sector and lever, to thereby vary the linespacmg rotation of said driver and platen as derived from a given movement of said lever.

27. In a line-spacing mechanism, the combination With a revolubletypewriter-platen, a fulcrum-stud spaced apart from said platen, a reciprocatory line-space lever fulcrumed on said stud. a rotary platen-driver rotatable about said stud and geared to the platen, a

one-way clutch rotatable about said stud, said clutch having its driven member connected to said driver, means connecting the driving member of the clutch to said linespace lever, said latter connecting means including a reciprocatory sector, a fulcrum for said sector having its axis spaced from the axis of the line-space lever fulcrum, said sector being geared to said driving member and having an arm, a link connecting said arm to an arm of said lever, and means for.

about said stud and geared to the platen, a

one-way clutch rotatable about said stud, said clutch having its driven member connected to said driver, means connecting the driving member of the clutch to said linespace lever, said latter connecting means in cluding a reciprocatory sector, a fulcrum for said sector having its axis spaced from the axis of the line-space-lever fulcrum, said sector being geared to said driving member and having an arm, a link connecting'said arm to an arm of said lever, one of said arms having a shiftable element for varying the length of said one arm, and means adjustable at will, and effective upon said element for shifting and securing the same in different positions, to thereby vary the line-spacing rotation of said driver and platen, as derived from a given movement of said lever.

29. In a line-spacing mechanism, the combination with a revoluble typewriter-platen, a fulcrum-stud spaced apart from said platen, a reciprocatory line-space lever fulcrumed on said stud, a rotary platen-driver rotatable about said stud and geared to the platen, said lever having an arm of variable length embodied in an element shiftable toward and from the lever-fulcrum, an operating connection between said element and said driver, whereby reciprocation of said lever effects uni-directional line-space-efiecting rotation of said driver, and a manipulatable device carried by said lever effective upon said shift able element for changing, at-will, and securing the position of said element, to thereby vary the line-spacing rotation of said driver and platen, as derived from a given movement of said lever.

30. In a line-spacing mechanism, the combination with a revoluble typewritenplaten, a fulcrum-stud spaced apart from said platen, a reoiprocatory line-space lever fulcrumed on said stud, a rotary platen-driver rotatable about said stud and geared to the platen, said lever having an arm of variable length embodied in an element shiftable toward and from the lever-fulcrum, an operating connection between said element and said driver, whereby reciprocation of said lever effects uni-directional linespace-efiecting rotation of said driver, a manipulatable rotary cam carried by said lever and engaging said shiftable element for changing the position there of, at will, to thereby vary the line-spacing rotation of said driver and said platen, as derived from a given movement of said lever,

and means for securing said cam, to thereby secure said element in its different positions.

31. In a line-spacing mechanism, the combination with a revoluble typewriter-platen, a fulcrum-stud spaced apart from said platen, a reciprocatory line-space lever fulcrumed on said stud, a rotary platen-driver rotatable about said stud'and geared to the platen, said lever having an arm of variable length embodied in an element shiftable toward and from the lever-fulcrum, an operating connection between said element and said driver, whereby reciprocation of said lever effectsuni-directional line-space-efiecting rotation of said driver, a manipulatable rotary cam carried by said lever, and for compactness arranged to rotate about the axis of the lever-fulcrum, said cam having a camsurface which engages said element and ranges toward and away from said fulcrum so that by rotation of said cam said element may be shifted to vary the line-spacing rotation of said driver and platen, as derived from a given movement of said lever, and means for securing said cam, to thereby secure said element in its different positions.

39. In a variable line-spacing mechanism, the combination of a reciprocatory line-space lever having a shiftable element forming a mechanism actuating arm of variable length, a fulcrum-stud for said lever, said lever having a hub bearing upon said stud, said hub extending beyond the body-portion of said lever, a cam-member designed for rotation concentrically about said hub and having a surface extending transversely of its axis of rotation, said surface having a cam-groove engaging said element so that said element may be shifted by rotating said cam-member, said lever having a seat for said cam-member disposed so that a space is formed between said cam-member surface and the body of said lever, said cam-member having a central hole larger than the diameter of said hub to form with said hub an annular space, and a lever-retracting spring retained within said space and having one portion connected to said lever, another portion of said spring projecting through the space formed, as aforesaid, between said cam-member surface and the body of said lever, said latter spring-portion projecting through said lat-fter space for reaction against a suitable abutment external to said lever.

33. In a variable line-spacing mechanism, the combination of reciprocatory line-space lever having a shiftable element forming a mechanism-actuating arm of variable length,

a fulcrum-stud for said lever, said lever having a hub bearing upon said stud, said hub extending beyond the body-portion of said lever, a cam-member designed for rotation concentrically about said huband'having a surface extending transversely of its axis of rotation, said surfacehaving a cam-groove 

